HIV infection is a major cause of morbidity and mortality among women worldwide. Few of the factors that increase susceptibility of women to HIV infection are known, and the development of woman-controlled HIV prevention methods is slow at best. We propose providing intensive logistical and field support of studies that link reproductive biology, HIV pathogenesis and pharmacology with regards to HIV. The goals of the Clinical and Data Core are to: 1) generate human subjects protocols, recruit, determine eligibility, and retain participants for program studies. 2) collect or obtain data, semen, cervical fluids and brushes, ecto- and endo-cervical and endometrial specimens for program studies according to each project's specifications, 3) measure tenofovir levels within cervical and endometrial tissues in the local Women's Interagency HIV Study (WIHS) participants of the WIHS pharmokinetics research, 4) obtain vaginal fluids from healthy women and women with bacterial vaginosis for studies of semen factors that influence male to female HIV transmission, 5) to interface with WIHS in conducting functional, transcriptome and immunohistochemistry studies of endometrial, ileal and sigmoid colon tissues that will be obtained by WIHS as part of its pathogenesis program. This application proposes a group of highly collaborative research projects that have intersecting data and specimen needs. Offering these resources via a single Core eliminates the need for redundant effort, ensures the efficient distribution of valuable samples, and frees laboratory-based investigators from supervising field activities. To the greatest extent possible use of existing data and specimens will be used, and when new recruitment is needed, we will endeavor to address the needs of multiple studies parsimoniously.